pipe2d-1176-fix.png
Spectra (4).png
[PIPE2D-1176] Sky subtraction removes only c. 50% of the sky flux Created: 02/Mar/23 Updated: 28/Apr/23 Resolved: 28/Apr/23 |
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| Status: | Done |
| Project: | DRP 2-D Pipeline |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Story | Priority: | Normal |
| Reporter: | rhl | Assignee: | price |
| Resolution: | Done | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Attachments: |
pipe2d-1176-fix.png
Spectra (4).png
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| Description |
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While looking at spectra from the 2022-11 run I noticed that fibre 437 appears to have only had c. half of the sky flux removed. For comparison, fibres 435 and 436 look OK. fid target status spot norm mag 435 SCIENCE GOOD 1.000 0.755 15.75 436 SKY GOOD 1.000 1.019 NaN 437 SCIENCE GOOD 1.000 0.652 15.73 |
| Comments |
| Comment by price [ 15/Mar/23 ] |
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It looks like this is due to fiberId=437 being near a black spot (distance = 0.77 mm) for the quartz observation used to construct the fiber profiles. I'll add the black spot correction to this part of the code too. |
| Comment by yuki.moritani [ 15/Mar/23 ] |
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Probably this is off topic (I'm sorry) ... At present, we are taking quarts/arc data at home position, at which some fiber suffer from the dot penumbra.. Is it better to move cobras to obscuration-free position? |
| Comment by price [ 15/Mar/23 ] |
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Unless there is a clear need to have the cobras at particular positions (e.g., repeating sky observations for some reason, hiding cobras behind black spots), all calibs should be taken with all the cobras completely un-obscured. The obscuration wastes photons and if it doesn't degrade the quality, at least makes the interpretation of the calibs more difficult. |
| Comment by price [ 16/Mar/23 ] |
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Applying the black spot correction to the quartz fixed the problem, as shown below.
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| Comment by price [ 28/Apr/23 ] |
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Merged along with |
